def milenage_auts(opc: bytes, k: bytes, rand: bytes,
auts: bytes) -> Optional[bytes]:
"""Validate AUTS. If successful, returns SQN_MS"""
amf = b'\x00\x00' # TS 33.102 Section 6.3.3
m = Milenage(None)
m.set_opc(opc)
ak = m.f5star(k, rand)
sqn_ak = auts[:6]
sqn = xor_buf(sqn_ak, ak[:6])
mac_s = m.f1star(k, rand, sqn, amf)
if mac_s == auts[6:14]:
return sqn
else:
return False
class AuC:
"""3GPP Authentication Centre
use the AuC.db file with (IMSI, K, SQN[, OP]) records to produce 2G, 3G or
4G auth vectors, and resynchronize SQN
"""
# verbosity level: list of log types to be displayed
DEBUG = ('ERR', 'WNG', 'INF', 'DBG')
AUC_DB_PATH = os.path.dirname(os.path.abspath(__file__)) + os.sep
#AUC_DB_PATH = 'C:\Python27\Lib\sitepackages\pycrate_corenet\'
# when rewriting the AuC.db, do a back-up of the last version of the file
DO_BACKUP = True
# MNO OP diversification parameter
# The AuC supports also a per-subscriber OP, to be set optionally in the AuC.db database
OP = b'ffffffffffffffff'
# SQN incrementation when a resynch is required by a USIM card
SQN_SYNCH_STEP = 2
# PLMN restriction for returning 4G vectors
# provide a list of allowed PLMN, or None for disabling the filter
#PLMN_FILTER = ['20869']
PLMN_FILTER = None
def __init__(self):
"""start the AuC
open AuC.db file
parse it into self.db (dict), containing IMSI: (K, SQN [, OP])
IMSI: string of digits
K : 16 bytes buffer
ALG2: integer (0, 1, 2 or 3, identifies the 2G auth algorithm)
SQN : unsigned integer
OP : subscriber specific OP, distinct from self.OP, optional field
"""
self.db = {}
try:
# get 3G authentication database AuC.db
db_fd = open('%sAuC.db' % self.AUC_DB_PATH, 'r')
# parse it into a dict object with IMSI as key
for line in db_fd.readlines():
if line[0] != '#' and line.count(';') >= 3:
fields = line[:-1].split(';')
IMSI = str(fields[0])
K = unhexlify(fields[1].encode('ascii'))
ALG2 = int(fields[2])
SQN = int(fields[3])
if len(fields) > 4 and len(fields) == 32:
OP = unhexlify(fields[4].encode('ascii'))
else:
OP = None
self.db[IMSI] = [K, ALG2, SQN, OP]
self._log('INF',
'AuC.db file opened: %i record(s) found' % len(self.db))
# close the file
db_fd.close()
except Exception as err:
self._log('ERR',
'unable to read AuC.db, path: %s' % self.AUC_DB_PATH)
raise (err)
self._save_required = False
#
# initiatlize the Milenage algo with the AuC-defined OP
self.Milenage = Milenage(self.OP)
#
self._log('DBG', 'AuC started')
def _log(self, logtype='DBG', msg=''):
if logtype in self.DEBUG:
log('[%s] [AuC] %s' % (logtype, msg))
def save(self):
"""
optionally save old AuC.db with timestamp suffix (if self.DO_BACKUP is set)
write the current content of self.db dict into AuC.db, with updated SQN
values
"""
if not self._save_required:
return
T = timemod.strftime('20%y%m%d_%H%M', timemod.gmtime())
# get header from original file AuC.db
header = []
file_db = open('%sAuC.db' % self.AUC_DB_PATH)
for line in file_db:
if line[0] == '#':
header.append(line)
else:
break
header = ''.join(header) + '\n'
file_db.close()
if self.DO_BACKUP:
# save the last current version of AuC.db
os.rename('%sAuC.db' % self.AUC_DB_PATH,
'%sAuC.%s.db' % (self.AUC_DB_PATH, T))
self._log('DBG', 'old AuC.db saved with timestamp')
# save the current self.db into a new AuC.db file
file_db = open('%s/AuC.db' % self.AUC_DB_PATH, 'w')
file_db.write(header)
indexes = list(self.db.keys())
indexes.sort()
for IMSI in indexes:
K, ALG2, SQN, OP = self.db[IMSI]
if OP is not None:
# OP additional parameter
file_db.write('%s;%s;%i;%i;%s;\n'\
% (IMSI, hexlify(K).decode('ascii'), ALG2, SQN, hexlify(OP).decode('ascii')))
else:
file_db.write('%s;%s;%i;%i;\n'\
% (IMSI, hexlify(K).decode('ascii'), ALG2, SQN))
file_db.close()
self._log('INF', 'current db saved to AuC.db file')
stop = save
def make_2g_vector(self, IMSI, RAND=None):
"""
return a 2G authentication vector "triplet":
RAND [16 bytes], RES [4 bytes], Kc [8 bytes]
or None if the IMSI is not defined in the db or ALG2 is invalid
RAND can be passed as argument
"""
# lookup db for authentication Key and algorithm id for IMSI
try:
K, ALG2, SQN, OP = self.db[IMSI]
except KeyError:
self._log('WNG',
'[make_2g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
#
if not RAND:
RAND = genrand(16)
#
if ALG2 == 0:
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345(RAND, K, OP)
else:
XRES, CK, IK, AK = self.Milenage.f2345(RAND, K)
RES, Ck = conv_C2(XRES), conv_C3(CK, IK)
else:
if ALG2 == 1:
RES, Ck = comp128v1(K, RAND)
elif ALG2 == 2:
RES, Ck = comp128v2(K, RAND)
elif ALG2 == 3:
RES, Ck = comp128v3(K, RAND)
else:
return None
#
# return auth vector
self._log('DBG', '[make_2g_vector] IMSI %s: RAND %s, RES %s, Kc %s'\
% (IMSI, hexlify(RAND).decode('ascii'), hexlify(RES).decode('ascii'),
hexlify(Kc).decode('ascii')))
return RAND, RES, Kc
def make_3g_vector(self, IMSI, AMF=b'\0\0', RAND=None):
'''
return a 3G authentication vector "quintuplet":
RAND [16 bytes], XRES [8 bytes], AUTN [16 bytes], CK [16 bytes], IK [16 bytes]
or None if the IMSI is not defined in the db or does not support Milenage
RAND can be passed as argument
'''
# lookup db for authentication Key and counter for IMSI
try:
K_ALG2_SQN_OP = self.db[IMSI]
except:
self._log('WNG',
'[make_3g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
#
K, ALG2, SQN, OP = K_ALG2_SQN_OP
#
if SQN == -1:
# Milenage not supported
self._log(
'WNG',
'[make_3g_vector] IMSI %s does not support Milenage' % IMSI)
return None
#
# increment SQN counter in the db
K_ALG2_SQN_OP[2] += 1
self._save_required = True
# pack SQN from integer to a 48-bit buffer
SQNb = b'\0\0' + pack('>I', SQN)
# generate challenge if necessary
if RAND is None:
RAND = genrand(16)
# compute Milenage functions
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345(K, RAND, OP)
MAC_A = self.Milenage.f1(K, RAND, SQNb, AMF, OP)
AUTN = xor_buf(SQNb, AK) + AMF + MAC_A
else:
XRES, CK, IK, AK = self.Milenage.f2345(K, RAND)
MAC_A = self.Milenage.f1(K, RAND, SQNb, AMF)
AUTN = xor_buf(SQNb, AK) + AMF + MAC_A
# return auth vector
self._log('DBG', '[make_3g_vector] IMSI %s, SQN %i: RAND %s, XRES %s, AUTN %s, CK %s, IK %s'\
% (IMSI, SQN, hexlify(RAND).decode('ascii'), hexlify(XRES).decode('ascii'),
hexlify(AUTN).decode('ascii'), hexlify(CK).decode('ascii'),
hexlify(IK).decode('ascii')))
return RAND, XRES, AUTN, CK, IK
def make_4g_vector(self, IMSI, SN_ID, AMF=b'\x80\x00', RAND=None):
"""
return a 4G authentication vector "quadruplet":
RAND [16 bytes], XRES [8 bytes], AUTN [16 bytes], KASME [32 bytes]
or None if the IMSI is not defined in the db or does not support Milenage
or SN_ID is invalid or not allowed
SN_ID is the serving network identity, bcd-encoded buffer
RAND can be passed as argument
"""
if not isinstance(SN_ID, bytes_types) or len(SN_ID) != 3:
self._log(
'WNG', '[make_4g_vector] SN_ID invalid, %s' %
hexlify(SN_ID).decode('ascii'))
return None
elif self.PLMN_FILTER is not None and SN_ID not in self.PLMN_FILTER:
self._log(
'WNG', '[make_4g_vector] SN_ID not allowed, %s' %
hexlify(SN_ID).decode('ascii'))
return None
#
# lookup db for authentication Key and counter for IMSI
try:
K_ALG2_SQN_OP = self.db[IMSI]
except:
self._log('WNG',
'[make_4g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
#
K, ALG2, SQN, OP = K_ALG2_SQN_OP
#
if SQN == -1:
# Milenage not supported
self._log(
'WNG',
'[make_4g_vector] IMSI %s does not support Milenage' % IMSI)
return None
#
# increment SQN counter in the db
K_ALG2_SQN_OP[2] += 1
self._save_required = True
# pack SQN from integer to a 48-bit buffer
SQNb = b'\0\0' + pack('>I', SQN)
#
# generate challenge
if RAND is None:
RAND = genrand(16)
# compute Milenage functions
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345(K, RAND, OP)
MAC_A = self.Milenage.f1(K, RAND, SQNb, AMF, OP)
SQN_X_AK = xor_buf(SQNb, AK)
AUTN = SQN_X_AK + AMF + MAC_A
else:
XRES, CK, IK, AK = self.Milenage.f2345(K, RAND)
MAC_A = self.Milenage.f1(K, RAND, SQNb, AMF)
SQN_X_AK = xor_buf(SQNb, AK)
AUTN = SQN_X_AK + AMF + MAC_A
# convert to LTE master key
KASME = conv_A2(CK, IK, SN_ID, SQN_X_AK)
# return auth vector
self._log('DBG', '[make_4g_vector] IMSI %s, SQN %i, SN_ID %s: RAND %s, XRES %s, AUTN %s, KASME %s'\
% (IMSI, SQN, hexlify(SN_ID).decode('ascii'), hexlify(RAND).decode('ascii'),
hexlify(XRES).decode('ascii'), hexlify(AUTN).decode('ascii'),
hexlify(KASME).decode('ascii')))
return RAND, XRES, AUTN, KASME
def synch_sqn(self, IMSI, RAND, AUTS):
"""
synchronize the local counter SQN with AUTS provided by the USIM
in response to a given 3G or 4G authentication challenge (RAND, AMF)
return 0 on successful synch, 1 on unsuccessful synch due to invalid AUTS
or None if the IMSI is not defined in the db
"""
# lookup db for authentication Key and counter for IMSI
try:
K_ALG2_SQN_OP = self.db[IMSI]
except:
self._log('WNG',
'[synch_sqn] IMSI %s not present in AuC.db' % IMSI)
return None
#
K, ALG2, SQN, OP = K_ALG2_SQN_OP
#
if K_ALG2_SQN_OP[2] == -1:
# Milenage not supported
self._log(
'WNG',
'[make_3g_vector] IMSI %s does not support Milenage' % IMSI)
return None
#
# 33.102, section 6.3.3, for resynch, AMF is always null (0x0000)
AMF = b'\0\0'
#
# compute Milenage functions and unmask SQN
if OP is not None:
AK = self.Milenage.f5star(K, RAND, OP)
SQN_MS = xor_buf(AUTS[0:6], AK)
MAC_S = self.Milenage.f1star(K, RAND, SQN_MS, AMF, OP)
SQN_MSi = unpack('>Q', b'\0\0' + SQN_MS)[0]
else:
AK = self.Milenage.f5star(K, RAND)
SQN_MS = xor_buf(AUTS[0:6], AK)
MAC_S = self.Milenage.f1star(K, RAND, SQN_MS, AMF)
SQN_MSi = unpack('>Q', b'\0\0' + SQN_MS)[0]
self._log('DBG', '[synch_sqn] USIM resynchronization, SQN_MS %i, MAC_S %s'\
% (SQN_MSi, hexlify(MAC_S).decode('ascii')))
# authenticate the USIM
if MAC_S != AUTS[6:14]:
self._log(
'WNG',
'[synch_sqn] IMSI %s, USIM authentication failure' % IMSI)
return 1
# resynchronize local SQN value
K_ALG2_SQN_OP[2] = SQN_MSi + self.SQN_SYNCH_STEP
self._save_required = True
self._log(
'DBG', '[synch_sqn] IMSI %s, SQN resynchronized to %i' %
(IMSI, K_ALG2_SQN_OP[2]))
return 0
class personalize(object):
'''
Class to program sysmo-USIM-SJS1 card
takes the ADM code of the card (str of digits)
and a 3 digit serial number as argument to personalize the USIM card.
Makes use of the fixed parameters in this file header:
ICCID_pre, IMSI_pre, Ki_pre, OP,
HPLMN, PLMNsel, SPN
'''
def __init__(self, ADM, serial_number='000'):
# prepare data to write into the card
if not len(serial_number) == 3 or not serial_number.isdigit():
raise (Exception('serial: 3-digits required'))
self.ICCID = ICCID_pre + serial_number
self.ICCID += str(compute_luhn(self.ICCID))
self.IMSI = IMSI_pre + serial_number
self.K = Ki_pre + serial_number
self.Milenage = Milenage(OP)
self.OPc = make_OPc(self.K, OP)
# verify parameters
if len(self.K) != 16 or len(self.OPc) != 16:
raise (Exception('K / OPc: 16-bytes buffer required'))
#
# write data on the card
u = UICC()
program_files(u, ADM, self.ICCID, self.IMSI, self.K, self.OPc)
u.disconnect()
#
if self.test_identification() != 0:
return
#
self._auth = 0
if self.test_authentication() != 0:
return
#
# and print results
print(
'[+] sysmoUSIM-SJS1 card personalization done and tested successfully:'
)
print('ICCID ; IMSI ; K ; OPc')
print('%s;%s;0x%s;0x%s' %
(self.ICCID, self.IMSI, hexlify(self.K), hexlify(self.OPc)))
def test_identification(self):
u = UICC()
iccid = u.get_ICCID()
u.disconnect()
u = USIM()
imsi = u.get_imsi()
u.disconnect()
#
if not iccid or not imsi:
raise (Exception('identification test error'))
return 1
else:
print('[+] USIM identification:\nICCID: %s\nIMSI: %s' %
(iccid, imsi))
return 0
def test_authentication(self):
if self._auth > 2:
return 1
#
# prepare dummy 128 bits auth challenge
if not hasattr(self, 'RAND'):
self.RAND = 16 * b'\x44'
if not hasattr(self, 'SQN'):
# default SQN is 0, coded on 48 bits
self.SQN = 0
# management field, unneeded, left blank
AMF = b'\0\0'
#
# compute Milenage functions
XRES, CK, IK, AK = self.Milenage.f2345(self.K, self.RAND)
MAC_A = self.Milenage.f1(self.K, self.RAND, sqn_to_str(self.SQN), AMF)
AUTN = xor_buf(sqn_to_str(self.SQN), AK) + AMF + MAC_A
#
# run auth data on the USIM
self.U = USIM()
ret = self.U.authenticate(stringToByte(self.RAND), stringToByte(AUTN),
'3G')
self.U.disconnect()
self._auth += 1
#
# check results (and pray)
if ret == None:
print('[-] authenticate() failed, something wrong happened')
del self.RAND
return 1
#
elif len(ret) == 1:
print(
'[-] sync failure during authenticate() with SQN %i, unmasking counter'
% self.SQN)
auts = byteToString(ret[0])
ak = self.Milenage.f5star(self.K, self.RAND)
self.SQN = str_to_sqn(xor_buf(auts, ak)[:6])
print('[+] SQN counter value in USIM: %i' % self.SQN)
self.SQN += 1 << 5
print('[+] retrying authenticate() with SQN: %i' % self.SQN)
del self.RAND
return self.test_authentication()
#
elif len(ret) in (3, 4):
# RES, CK, IK(, Kc)
if ret[0:3] == map(stringToByte, [XRES, CK, IK]):
print(
'[+] 3G auth successful with SQN: %i\nincrement it from now'
% self.SQN)
print('[+] USIM secrets:\nOPc: %s\nK: %s' %
(hexlify(self.OPc), hexlify(self.K)))
else:
print(
'[-] 3G auth accepted on the USIM, but not matching auth vector generated: strange!'
)
print('card returned:\n%s' % ret)
del self.RAND
return 0
#
else:
print('[-] undefined auth error')
del self.RAND
return 1
class personalize(object):
'''
Class to program sysmo-USIM-SJS1 card
takes the ADM code of the card (str of digits)
and a 3 digit serial number as argument to personalize the USIM card.
Makes use of the fixed parameters in this file header:
ICCID_pre, IMSI_pre, Ki_pre, OP,
HPLMN, PLMNsel, SPN
'''
def __init__(self, ADM, serial_number='000'):
# prepare data to write into the card
if not len(serial_number) == 3 or not serial_number.isdigit():
raise(Exception('serial: 3-digits required'))
self.ICCID = ICCID_pre + serial_number
self.ICCID += str(compute_luhn(self.ICCID))
self.IMSI = IMSI_pre + serial_number
self.K = Ki_pre + serial_number
self.Milenage = Milenage(OP)
self.OPc = make_OPc(self.K, OP)
# verify parameters
if len(self.K) != 16 or len(self.OPc) != 16:
raise(Exception('K / OPc: 16-bytes buffer required'))
#
# write data on the card
u = UICC()
program_files(u, ADM, self.ICCID, self.IMSI, self.K, self.OPc)
u.disconnect()
#
if self.test_identification() != 0:
return
#
self._auth = 0
if self.test_authentication() != 0:
return
#
# and print results
print('[+] sysmoUSIM-SJS1 card personalization done and tested successfully:')
print('ICCID ; IMSI ; K ; OPc')
print('%s;%s;0x%s;0x%s' % (self.ICCID, self.IMSI, hexlify(self.K), hexlify(self.OPc)))
def test_identification(self):
u = UICC()
iccid = u.get_ICCID()
u.disconnect()
u = USIM()
imsi = u.get_imsi()
u.disconnect()
#
if not iccid or not imsi:
raise(Exception('identification test error'))
return 1
else:
print('[+] USIM identification:\nICCID: %s\nIMSI: %s' % (iccid, imsi))
return 0
def test_authentication(self):
if self._auth > 2:
return 1
#
# prepare dummy 128 bits auth challenge
if not hasattr(self, 'RAND'):
self.RAND = 16*b'\x44'
if not hasattr(self, 'SQN'):
# default SQN is 0, coded on 48 bits
self.SQN = 0
# management field, unneeded, left blank
AMF = b'\0\0'
#
# compute Milenage functions
XRES, CK, IK, AK = self.Milenage.f2345( self.K, self.RAND )
MAC_A = self.Milenage.f1(self.K, self.RAND, sqn_to_str(self.SQN), AMF)
AUTN = xor_buf(sqn_to_str(self.SQN), AK) + AMF + MAC_A
#
# run auth data on the USIM
self.U = USIM()
ret = self.U.authenticate(stringToByte(self.RAND), stringToByte(AUTN), '3G')
self.U.disconnect()
self._auth += 1
#
# check results (and pray)
if ret == None:
print('[-] authenticate() failed, something wrong happened')
del self.RAND
return 1
#
elif len(ret) == 1:
print('[-] sync failure during authenticate() with SQN %i, unmasking counter' % self.SQN)
auts = byteToString(ret[0])
ak = self.Milenage.f5star(self.K, self.RAND)
self.SQN = str_to_sqn(xor_buf(auts, ak)[:6])
print('[+] SQN counter value in USIM: %i' % self.SQN)
self.SQN += 1<<5
print('[+] retrying authenticate() with SQN: %i' % self.SQN)
del self.RAND
return self.test_authentication()
#
elif len(ret) in (3, 4):
# RES, CK, IK(, Kc)
if ret[0:3] == map(stringToByte, [XRES, CK, IK]):
print('[+] 3G auth successful with SQN: %i\nincrement it from now' % self.SQN)
print('[+] USIM secrets:\nOPc: %s\nK: %s' % (hexlify(self.OPc), hexlify(self.K)))
else:
print('[-] 3G auth accepted on the USIM, but not matching auth vector generated: strange!')
print('card returned:\n%s' % ret)
del self.RAND
return 0
#
else:
print('[-] undefined auth error')
del self.RAND
return 1
class AuC:
"""3GPP Authentication Centre (AuC), ARPF and SIDF
Use the AuC.db file with (IMSI, K, SQN[, OP]) records to then produce 2G, 3G,
4G or 5G authentication vectors, and resynchronize SQN. It supports all standard
authentication algorithms: comp123v1, v2, v3, Milenage and TUAK.
Set SIDF home-network private keys for profile A and / or B and use it to decrypt
concealed subscriber 5G identities.
"""
# verbosity level: list of log types to be displayed
DEBUG = ('ERR', 'WNG', 'INF', 'DBG')
# path to the local AuC.db file, should be overwritten
AUC_DB_PATH = os.path.dirname(os.path.abspath( __file__ )) + os.sep
# when rewriting the AuC.db, do a back-up of the last version of the file
DO_BACKUP = True
# MNO OP (Milenage) and TOP (TUAK) diversification parameter
# The AuC supports also a per-subscriber OP / TOP, to be set optionally in the AuC.db database
OP = b'ffffffffffffffff'
TOP = b'ffffffffffffffffffffffffffffffff'
# SQN incrementation when a resynch is required by a USIM card
SQN_SYNCH_STEP = 2
# PLMN restriction for returning 4G and 5G vectors
# provide a list of allowed PLMN, or None for disabling the filter
#PLMN_FILTER = ['20869']
PLMN_FILTER = None
# SIDF ECIES private keys dict, for decrypting SUCI
# index: Home Network Public Key Identifier (0..255), according to TS 31.102, section 4.4.11.8
# value: 2-tuple with Protection Scheme Identifier (profile 'A' or 'B') and
# corresponding Home Network Private Key value
#
# ECIES public / private keypairs must be generated according to the CryptoMobile.ECIES API
#
SIDF_ECIES_K = {
#
# X25519 example keypair (WARNING: use one you generated yourself):
# pubkey: d6797fcf69c55e889e5bdf9fc4d300eff2aa5b539bb9e97efe14ca244727b029
#0 : ('A', unhexlify('38859b29cbbdee43fda218968f8b96bb9a7326ec05b43343939220fa2ac1ec56')),
#
# secp256r1 example keypair (WARNING: use one you generated yourself):
# pubkey: 02519c4707c3535eb5a86a66d056696a45537d4d76e8997375dcd7d30b1f37c6c5
#1 : ('B', unhexlify('308187020100301306072a8648ce3d020106082a8648ce3d030107046d306b02'\
# '01010420d633fa02b1808226c0a27ddf093e332751f10cb002e8236d3723bb44'\
# '33a55d41a14403420004519c4707c3535eb5a86a66d056696a45537d4d76e899'\
# '7375dcd7d30b1f37c6c50fb946aec017a332ff00e3993f35b54992004894f7d2'\
# 'fc1ee0df47fde0c91cf8')
}
def __init__(self):
"""start the AuC
open AuC.db file
parse it into self.db (dict), containing IMSI: (K, SQN [, OP])
IMSI: string of digits
K : 16 bytes buffer
ALG : integer (0, 1, 2, 3 or 4, identifies the auth algorithm)
SQN : unsigned integer
OP : subscriber specific OP, distinct from self.OP, optional field
"""
self.db = {}
try:
# get 3G authentication database AuC.db
db_fd = open('%sAuC.db' % self.AUC_DB_PATH, 'r')
# parse it into a dict object with IMSI as key
for line in db_fd.readlines():
if line[0] != '#' and line.count(';') >= 3:
fields = line[:-1].split(';')
IMSI = str( fields[0] )
K = unhexlify( fields[1].encode('ascii') )
ALG = int( fields[2] )
SQN = int( fields[3] )
if len(fields) > 4 and len(fields[4]) == 32:
OP = unhexlify( fields[4].encode('ascii') )
else:
OP = None
self.db[IMSI] = [ K, ALG, SQN, OP ]
self._log('INF', 'AuC.db file opened: %i record(s) found' % len(self.db))
# close the file
db_fd.close()
except Exception as err:
self._log('ERR', 'unable to read AuC.db, path: %s' % self.AUC_DB_PATH)
raise(err)
self._save_required = False
#
# initialize the Milenage algo with the AuC-defined OP
self.Milenage = Milenage(self.OP)
# initialize the TUAK algo with the AuC-defined TOP
self.TUAK = TUAK(self.TOP)
# initialize the SIDF function
self._init_sidf()
#
self._log('DBG', 'AuC / ARPF / SIDF started')
def _init_sidf(self):
self._SIDF_ECIES = {}
for ind, (prof, key) in self.SIDF_ECIES_K.items():
self._SIDF_ECIES[ind] = ECIES_HN(hn_priv_key=key, profile=prof)
def _log(self, logtype='DBG', msg=''):
if logtype in self.DEBUG:
log('[%s] [AuC] %s' % (logtype, msg))
def save(self):
"""
optionally save old AuC.db with timestamp suffix (if self.DO_BACKUP is set)
write the current content of self.db dict into AuC.db, with updated SQN
values
"""
if not self._save_required:
return
T = timemod.strftime( '20%y%m%d_%H%M', timemod.gmtime() )
# get header from original file AuC.db
header = []
file_db = open('%sAuC.db' % self.AUC_DB_PATH)
for line in file_db:
if line[0] == '#':
header.append( line )
else:
break
header = ''.join(header) + '\n'
file_db.close()
if self.DO_BACKUP:
# save the last current version of AuC.db
os.rename( '%sAuC.db' % self.AUC_DB_PATH,
'%sAuC.%s.db' % (self.AUC_DB_PATH, T) )
self._log('DBG', 'old AuC.db saved with timestamp')
# save the current self.db into a new AuC.db file
file_db = open('%s/AuC.db' % self.AUC_DB_PATH, 'w')
file_db.write( header )
indexes = list(self.db.keys())
indexes.sort()
for IMSI in indexes:
K, ALG, SQN, OP = self.db[IMSI]
if OP is not None:
# OP additional parameter
file_db.write('%s;%s;%i;%i;%s;\n'\
% (IMSI, hexlify(K).decode('ascii'), ALG, SQN, hexlify(OP).decode('ascii')))
else:
file_db.write('%s;%s;%i;%i;\n'\
% (IMSI, hexlify(K).decode('ascii'), ALG, SQN))
file_db.close()
self._log('INF', 'current db saved to AuC.db file')
stop = save
def make_2g_vector(self, IMSI, RAND=None):
"""
return a 2G authentication vector "triplet":
RAND [16 bytes], RES [4 bytes], Kc [8 bytes]
or None if the IMSI is not defined in the db or ALG is invalid
RAND can be passed as argument
"""
# lookup db for authentication Key and algorithm id for IMSI
try:
K_ALG_SQN_OP = self.db[IMSI]
except KeyError:
self._log('WNG', '[make_2g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
if len(K_ALG_SQN_OP) == 4:
K, ALG, SQN, OP = K_ALG_SQN_OP
else:
K, ALG, SQN = K_ALG_SQN_OP
OP = None
#
if not RAND:
RAND = genrand(16)
#
if ALG == 0:
# Milenage, adapted to 2G
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345(RAND, K, OP)
else:
XRES, CK, IK, AK = self.Milenage.f2345(RAND, K)
RES, Kc = conv_102_C2(XRES), conv_102_C3(CK, IK)
elif ALG == 4:
# TUAK, adapted to 2G
if OP is not None:
# which is actually TOP, for TUAK
XRES, CK, IK, AK = self.TUAK.f2345(RAND, K, OP)
else:
XRES, CK, IK, AK = self.TUAK.f2345(RAND, K)
RES, Kc = conv_102_C2(XRES), conv_102_C3(CK, IK)
else:
# COMP128
if ALG == 1:
RES, Kc = comp128v1(K, RAND)
elif ALG == 2:
RES, Kc = comp128v2(K, RAND)
elif ALG == 3:
RES, Kc = comp128v3(K, RAND)
else:
# invalid ALG
return None
#
# return auth vector
self._log('DBG', '[make_2g_vector] IMSI %s: RAND %s, RES %s, Kc %s'\
% (IMSI, hexlify(RAND).decode('ascii'), hexlify(RES).decode('ascii'),
hexlify(Kc).decode('ascii')))
return RAND, RES, Kc
def make_3g_vector(self, IMSI, AMF=b'\0\0', RAND=None):
'''
return a 3G authentication vector "quintuplet":
RAND [16 bytes], XRES [8 bytes], AUTN [16 bytes], CK [16 bytes], IK [16 bytes]
or None if the IMSI is not defined in the db or does not support Milenage or TUAK
RAND can be passed as argument
'''
# lookup db for authentication Key and counter for IMSI
try:
K_ALG_SQN_OP = self.db[IMSI]
except Exception:
self._log('WNG', '[make_3g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
if len(K_ALG_SQN_OP) == 4:
K, ALG, SQN, OP = K_ALG_SQN_OP
else:
K, ALG, SQN = K_ALG_SQN_OP
OP = None
#
if SQN == -1:
# Milenage / TUAK not supported
self._log('WNG', '[make_3g_vector] IMSI %s does not support Milenage / TUAK' % IMSI)
return None
#
# increment SQN counter in the db
K_ALG_SQN_OP[2] += 1
self._save_required = True
#
# pack SQN from integer to a 48-bit buffer
SQNb = pack('>Q', SQN)[2:]
#
# generate challenge if necessary
if RAND is None:
RAND = genrand(16)
#
if ALG == 0:
# compute Milenage functions
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345( K, RAND, OP )
MAC_A = self.Milenage.f1( K, RAND, SQNb, AMF, OP )
else:
XRES, CK, IK, AK = self.Milenage.f2345( K, RAND )
MAC_A = self.Milenage.f1( K, RAND, SQNb, AMF )
elif ALG == 4:
# compute TUAK functions
if OP is not None:
XRES, CK, IK, AK = self.TUAK.f2345( K, RAND, OP )
MAC_A = self.TUAK.f1( K, RAND, SQNb, AMF, OP )
else:
XRES, CK, IK, AK = self.TUAK.f2345( K, RAND )
MAC_A = self.TUAK.f1( K, RAND, SQNb, AMF )
else:
# invalid ALG
return None
#
AUTN = xor_buf( SQNb, AK ) + AMF + MAC_A
#
# return auth vector
self._log('DBG', '[make_3g_vector] IMSI %s, SQN %i: RAND %s, XRES %s, AUTN %s, CK %s, IK %s'\
% (IMSI, SQN, hexlify(RAND).decode('ascii'), hexlify(XRES).decode('ascii'),
hexlify(AUTN).decode('ascii'), hexlify(CK).decode('ascii'),
hexlify(IK).decode('ascii')))
return RAND, XRES, AUTN, CK, IK
def make_4g_vector(self, IMSI, SN_ID, AMF=b'\x80\x00', RAND=None):
"""
return a 4G authentication vector "quadruplet":
RAND [16 bytes], XRES [8 bytes], AUTN [16 bytes], KASME [32 bytes]
or None if the IMSI is not defined in the db or does not support Milenage or TUAK
or SN_ID is invalid or not allowed
SN_ID is the serving network identity, bcd-encoded buffer
RAND can be passed as argument
"""
if not isinstance(SN_ID, bytes_types) or len(SN_ID) != 3:
self._log('WNG', '[make_4g_vector] SN_ID invalid, %s' % hexlify(SN_ID).decode('ascii'))
return None
elif self.PLMN_FILTER is not None and SN_ID not in self.PLMN_FILTER:
self._log('WNG', '[make_4g_vector] SN_ID not allowed, %s' % hexlify(SN_ID).decode('ascii'))
return None
#
# lookup db for authentication Key and counter for IMSI
try:
K_ALG_SQN_OP = self.db[IMSI]
except Exception:
self._log('WNG', '[make_4g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
if len(K_ALG_SQN_OP) == 4:
K, ALG, SQN, OP = K_ALG_SQN_OP
else:
K, ALG, SQN = K_ALG_SQN_OP
OP = None
#
if ALG not in (0, 4):
# Milenage / TUAK not supported
self._log('WNG', '[make_4g_vector] IMSI %s does not support Milenage or TUAK' % IMSI)
return None
#
# increment SQN counter in the db
if SQN >= 0:
K_ALG_SQN_OP[2] += 1
self._save_required = True
#
# pack SQN from integer to a 48-bit buffer
SQNb = pack('>Q', SQN)[2:]
#
# generate challenge
if RAND is None:
RAND = genrand(16)
#
if ALG == 0:
# compute Milenage functions
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345( K, RAND, OP )
MAC_A = self.Milenage.f1( K, RAND, SQNb, AMF, OP )
else:
XRES, CK, IK, AK = self.Milenage.f2345( K, RAND )
MAC_A = self.Milenage.f1( K, RAND, SQNb, AMF )
else:
# ALG == 4, compute TUAK functions
if OP is not None:
XRES, CK, IK, AK = self.TUAK.f2345( K, RAND, OP )
MAC_A = self.TUAK.f1( K, RAND, SQNb, AMF, OP )
else:
XRES, CK, IK, AK = self.TUAK.f2345( K, RAND )
MAC_A = self.TUAK.f1( K, RAND, SQNb, AMF )
#
SQN_X_AK = xor_buf( SQNb, AK )
AUTN = SQN_X_AK + AMF + MAC_A
# convert to LTE master key
KASME = conv_401_A2(CK, IK, SN_ID, SQN_X_AK)
#
# return auth vector
self._log('DBG', '[make_4g_vector] IMSI %s, SQN %i, SN_ID %s: RAND %s, XRES %s, AUTN %s, KASME %s'\
% (IMSI, SQN, hexlify(SN_ID).decode('ascii'), hexlify(RAND).decode('ascii'),
hexlify(XRES).decode('ascii'), hexlify(AUTN).decode('ascii'),
hexlify(KASME).decode('ascii')))
return RAND, XRES, AUTN, KASME
def make_5g_vector(self, IMSI, SNName, AMF=b'\x80\x00', RAND=None):
"""
return a 5G authentication vector "quadruplet":
RAND [16 bytes], XRES* [8 bytes], AUTN [16 bytes], KAUSF [32 bytes]
or None if the IMSI is not defined in the db or does not support Milenage or TUAK
or SNName is invalid or not allowed
SNName is the serving network name, ascii-encoded bytes buffer
RAND can be passed as argument
"""
if not isinstance(SNName, bytes_types) or not 32 <= len(SNName) <= 255:
self._log('WNG', '[make_5g_vector] SNName invalid, %s' % SNName.decode('ascii'))
return None
elif self.PLMN_FILTER is not None:
# extract MCC, MNC from SNName (e.g. "5G:mnc012.mcc345.3gppnetwork.org")
snname_parts = SNName.split(':')[1].split('.')
mcc, mnc = snname_parts[1][3:], snname_parts[0][3:]
if mcc + mnc not in self.PLMN_FILTER:
self._log('WNG', '[make_5g_vector] SNName not allowed, %s' % SNName.decode('ascii'))
return None
#
# lookup db for authentication Key and counter for IMSI
try:
K_ALG_SQN_OP = self.db[IMSI]
except Exception:
self._log('WNG', '[make_5g_vector] IMSI %s not present in AuC.db' % IMSI)
return None
if len(K_ALG_SQN_OP) == 4:
K, ALG, SQN, OP = K_ALG_SQN_OP
else:
K, ALG, SQN = K_ALG_SQN_OP
OP = None
#
if ALG not in (0, 4):
# Milenage / TUAK not supported
self._log('WNG', '[make_4g_vector] IMSI %s does not support Milenage or TUAK' % IMSI)
return None
#
# increment SQN counter in the db
if SQN >= 0:
K_ALG_SQN_OP[2] += 1
self._save_required = True
#
# pack SQN from integer to a 48-bit buffer
SQNb = pack('>Q', SQN)[2:]
#
# generate challenge
if RAND is None:
RAND = genrand(16)
#
if ALG == 0:
# compute Milenage functions
if OP is not None:
XRES, CK, IK, AK = self.Milenage.f2345( K, RAND, OP )
MAC_A = self.Milenage.f1( K, RAND, SQNb, AMF, OP )
else:
XRES, CK, IK, AK = self.Milenage.f2345( K, RAND )
MAC_A = self.Milenage.f1( K, RAND, SQNb, AMF )
else:
# ALG == 4, compute TUAK functions
if OP is not None:
XRES, CK, IK, AK = self.TUAK.f2345( K, RAND, OP )
MAC_A = self.TUAK.f1( K, RAND, SQNb, AMF, OP )
else:
XRES, CK, IK, AK = self.TUAK.f2345( K, RAND )
MAC_A = self.TUAK.f1( K, RAND, SQNb, AMF )
#
SQN_X_AK = xor_buf( SQNb, AK )
AUTN = SQN_X_AK + AMF + MAC_A
# convert to AUSF master key
KAUSF = conv_501_A2(CK, IK, SNName, SQN_X_AK)
XRESstar = conv_501_A4(CK, IK, SNName, RAND, XRES)
#
# return auth vector
self._log('DBG', '[make_4g_vector] IMSI %s, SQN %i, SNName %s: RAND %s, XRES* %s, AUTN %s, KASME %s'\
% (IMSI, SQN, hexlify(SNName).decode('ascii'), hexlify(RAND).decode('ascii'),
hexlify(XRESstar).decode('ascii'), hexlify(AUTN).decode('ascii'),
hexlify(KAUSF).decode('ascii')))
return RAND, XRESstar, AUTN, KAUSF
def synch_sqn(self, IMSI, RAND, AUTS):
"""
synchronize the local counter SQN with AUTS provided by the USIM
in response to a given 3G or 4G authentication challenge (RAND, AMF)
return 0 on successful synch, 1 on unsuccessful synch due to invalid AUTS
or None if the IMSI is not defined in the db
"""
# lookup db for authentication Key and counter for IMSI
try:
K_ALG_SQN_OP = self.db[IMSI]
except Exception:
self._log('WNG', '[synch_sqn] IMSI %s not present in AuC.db' % IMSI)
return None
if len(K_ALG_SQN_OP) == 4:
K, ALG, SQN, OP = K_ALG_SQN_OP
else:
K, ALG, SQN = K_ALG_SQN_OP
OP = None
#
if ALG not in (0, 4):
# Milenage not supported
self._log('WNG', '[make_3g_vector] IMSI %s does not support Milenage or TUAK' % IMSI)
return None
#
# 33.102, section 6.3.3, for resynch, AMF is always null (0x0000)
AMF = b'\0\0'
#
if ALG == 0:
# compute Milenage functions
if OP is not None:
AK = self.Milenage.f5star( K, RAND, OP )
SQN_MS = xor_buf( AUTS[0:6], AK )
MAC_S = self.Milenage.f1star( K, RAND, SQN_MS, AMF, OP )
else:
AK = self.Milenage.f5star( K, RAND )
SQN_MS = xor_buf( AUTS[0:6], AK )
MAC_S = self.Milenage.f1star( K, RAND, SQN_MS, AMF )
else:
# ALG == 4, compute TUAK functions
if OP is not None:
AK = self.TUAK.f5star( K, RAND, OP )
SQN_MS = xor_buf( AUTS[0:6], AK )
MAC_S = self.TUAK.f1star( K, RAND, SQN_MS, AMF, OP )
else:
AK = self.TUAK.f5star( K, RAND )
SQN_MS = xor_buf( AUTS[0:6], AK )
MAC_S = self.TUAK.f1star( K, RAND, SQN_MS, AMF )
#
# unmask SQN
SQN_MSi = unpack('>Q', b'\0\0' + SQN_MS)[0]
#
self._log('DBG', '[synch_sqn] USIM resynchronization, SQN_MS %i, MAC_S %s'\
% (SQN_MSi, hexlify(MAC_S).decode('ascii')))
#
# authenticate the USIM
if MAC_S != AUTS[6:14]:
self._log('WNG', '[synch_sqn] IMSI %s, USIM authentication failure' % IMSI)
return 1
#
# resynchronize local SQN value
K_ALG_SQN_OP[2] = SQN_MSi + self.SQN_SYNCH_STEP
self._save_required = True
self._log('DBG', '[synch_sqn] IMSI %s, SQN resynchronized to %i' % (IMSI, K_ALG_SQN_OP[2]))
return 0
def sidf_unconceal(self, hnkid, ephpubk, cipht, mac):
"""
unconceal the cipher text `cipht` according to ECIES profile A or B (which
is implicitly depending on `hnkid`).
Use the home network private key index `hnkid`, ephemeral public key
`ephpubk`, after verifying the `mac`. All parameters are part of the
SUCI.
return None on error or the unconceal clear-text value bytes buffer (i.e.
the clear-text 5G subscriber identity)
"""
if hnkid not in self._SIDF_ECIES or not 32 <= len(ephpubk) <= 33 or len(mac) != 8:
self._log('WNG', '[sidf_unconceal] invalid parameter')
return None
#
try:
cleart = self._SIDF_ECIES[hnkid].unprotect(ephpubk, cipht, mac)
except Exception as err:
self._log('ERR', '[sidf_unconceal] EC processing error: %s' % err)
return None
else:
self._log('DBG', '[sidf_unconceal] SUCI ciphertext %s decrypted to %s'\
% (hexlify(cipht).decode('ascii'), hexlify(cleart).decode('ascii')))
return cleart